• Journal of Korean Society for Atmospheric Environment
• /
• v.12 no.3
• /
• pp.263-268
• /
• 1996

This study was conducted for the assessment of the effects of acid rain and soil fertilizers on photosynthetic rate, was content, and contact angle on 5-year seedlings of Japanese red pine (Pinus densiflora Sieb. et Zucc.) leaves. The seedlings were exposed to pH 3.0 (simulated acid rain), pH 6.5 (groung water) and rain (pH around 4.6). The seedlings were also treated with $Ca(OH)_2, Mg(OH)_2, and Ca(OH)_2 + Mg(OH)_2 + C.F.(compound fertilizer)$. Photosynthetic rate, stomatal conductance, was content, contact angle value, and mineral nutrient content of the leaves were measured and the results were as follows: 1. Photosynthetic rate and stomatal conductance of the leaves increased with the increase of pH. Photosynthetic rate and stomatal conductance increased with application of soil fertilizer in the pH 3.0 treatment, but showed no changes in the rain and the pH 6.5. 2. Contact angle value and was content of the leaves did not change with the pH treatment, but increased with the fertilizer treatments. 3. Mineral nutrient contents of the leaves were lowest in the rain treatment and highest in the pH 6.5 treatment. The increase of mineral nutrient contents was observed with the soil fertilizer treatments.

• Proceedings of the KSRS Conference
• /
• 2002.10a
• /
• pp.361-365
• /
• 2002

Rain-rate retrieval using the NOAA/AMSU (Advanced Microwave Sounding Unit) (Zaho et al., 2001) has been implemented at METRI/KMA since 2001. Here, we present the results of the AMSU derived rain-rate and validation result, especially for the rainfall associated with the tropical cyclone for 2001. For the validation, we use rain-rate derived from the ground based radar and/or rainfall observation from the rain gauge in Korea. We estimate the bias score, threat score, bias, RMSE and correlation coefficient for total of 16 tropical cyclone cases. Bias score shows around 1.3 and it increases with the increasing threshold value of rain-rate, while the threat score extends from 0.4 to 0.6 with the increasing threshold value of precipitation. The averaged rain-rate for at all 16 cases is 3.96mm/hr and 1.41mm/hr for the retrieved from AMSU and the ground observation, respectively. On the other hand, AMSU rain-rate shows a much better agreement with the ground based observation over inner part of tropical cyclone than over the outer part (Correlation coefficient for convective region is about 0.7, while it is only about 0.3 over the stratiform region). The larger discrepancy of tile correlation coefficient with the different part of the tropical cyclone is partly due to the time difference in between ice water path and surface rainfall. This results indicates that it might be better to develop the algorithm for different rain classes such as convective and stratiform.

• Proceedings of the KIEE Conference
• /
• 2002.11c
• /
• pp.210-213
• /
• 2002

This paper addresses the design and implementation of compensation of rain attenuation for Ka-band satellite communication system complied with DVB-RCS[2]. A structure of rain fade compensation scheme in the Ka-band satellite communication system is presented. Rain fade compensation scheme in this paper is mainly applied into return-link, which is the path through which user terminal transmit the data tn hub system providing a service. Symbol rate and code rate of channel code are used as variable transmission parameter for rain fade compensation. For estimation of channel environment, SNR of the user terminal which is measured by demodulator of hub system is used. Rain fade compensation scheme in the paper changes the symbol rate and/or code rate according to the measured SNR so that it can compensate the attenuation of the signal.

• ETRI Journal
• /
• v.29 no.4
• /
• pp.542-544
• /
• 2007

In this study, several methods to convert rain rate data for various time intervals to one-minute rates are compared. High-resolution tipping bucket precipitation records for seven locations in a tropical region are analyzed and compared using these conversion models. The Segal, Chebil, and Burgueno methods give the smallest average errors below 10% at different integration times.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.3 no.4
• /
• pp.779-785
• /
• 1999

The satellite signals have attenuation when Satellite path have rain. The signal attenuation by rain is effected over 100Hz and higher frequency signal have very serious attenuation. The rain attenuation is due mostly to rain rate and rain rate data over 10 years need to estimate characteristics of distribution of ram rate. In this paper, We have obtained the rain characteristics from on the recent data(1988-1997) for Changwon-Masan approximated with Moupfouma New Model, and then estimated the rain attenuation using ITU-R, Global and SAM methods, and finally, Effect of rain was analyzed.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.9 no.6
• /
• pp.345-351
• /
• 2014

This paper presents pedestrian recognition to improve performance for vehicle safety system or surveillance system. Pedestrian detection method using HOG (Histograms of Oriented Gradients) has showed 90% recognition rate. But if someone takes a picture in the rain, the image may be distorted by rain streaks and recognition rate goes down by 62%. To solve this problem, we applied image decomposition method using MCA (Morphological Component Analysis). In this case, rain removal method improves recognition rate from 62% to 70%. However, it is difficult to apply conventional image decomposition method using MCA on vehicle safety system or surveillance system as conventional method is too slow for real-time system. To alleviate this issue, we propose a rain removal method by using low-pass filter and DCT (Discrete Cosine Transform). The DCT helps separate the image into rain components. The image is removed rain components by Butterworth filtering. Experimental results show that our method achieved 90% of recognition rate. In addition, the proposed method had accelerated processing time to 17.8ms which is acceptable for real-time system.

• Atmosphere
• /
• v.20 no.3
• /
• pp.333-341
• /
• 2010

The stratiform rain fraction is investigated in the tropical boreal winter Madden-Julian oscillation (MJO) and summer intraseasonal oscillation (ISO) using Tropical Rainfall Measuring Mission (TRMM) Precipitation Rader data for the 11-yr period from 1998 to 2008. Composite analysis shows that the MJO/ISO produces larger stratiform rain rate than convective rain rate for nearly all phases following the propagating MJO/ISO deep clouds, with the greatest stratiform rainfall amount when the MJO/ISO center is located over the central-eastern Indian Ocean and the western Pacific. The fraction of the intraseasonally filtered stratiform rainfall compared to total rainfall (i.e., convective plus stratiform rainfall) amounts to 53~56%, which is 13~16% larger than the stratiform rain fraction estimated for the same data on seasonal-to-annual time scales by Schumacher and Houze. This indicates that the MJO/ISO exhibits the organized rainfall process which is characterized by the shallow convection/heating at the incipient phase and the subsequent flare-up of strong deep convection, followed by the development of stratiform clouds at the upper troposphere.

• Proceedings of the KSRS Conference
• /
• 1999.11a
• /
• pp.117-121
• /
• 1999

Relations between GMS-5 infrared brightness temperature with SSM/I retrieved rain rate are determined by a probability matching method similar to Atlas et al. and Crosson et al. For this study, coincident data sets of the GMS-5 infrared measurements and SSM/I data during two summer seasons of 1997 and 1998 are constructed. The cumulative density functions (CDFs) of infrared brightness temperature and rain rate are matched at pairs of two variables which give the same percentile contribution. The method was applied for estimating rain rate on 31 July 1998, examining heavy rainfall estimation of a flash flood event over Mt. Jiri. Results were compared with surface gauge observations run by Korean Meteorological Administration. It was noted that the method produced reasonably good quality of rain estimate, however, there was large area giving false rain due to the anvil type clouds surrounding deep convective clouds. Extensive validation against surface rain observation is currently under investigation.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.38 no.3
• /
• pp.41-49
• /
• 1996

One of the typically simple structures in protected horticulture is the rain shelter, which is widely applied in summer regardless of its poor ventilation. To evaluate ventilation performance of rain shelters, the ventilation rate as well as inside temperature of one conventional and two improved rain shelters were predicted and compared under various wind speeds and irradiations. More accurate model in which the inside space of rain shelter was subdivided into three parts considering the crops grown, was developed. The ventilation rate of each opening and the general direction of air flow in the rain shelter can be predicted by the model. The ventilation rates as well as inside temperatures of each rain shelter obtained by the model and the actual measurement, proved that the ventilation performance of improved rain shelters were superior to that of conventional one.

• Atmosphere
• /
• v.23 no.3
• /
• pp.265-273
• /
• 2013

To investigate properties of cloud and rainfall occurred at Boseong on 10 July 2012, Raindrop Size distributions (RSDs) and other parameters were analyzed using observation data collected by Micro Rain Radar (MRR) and PARticle SIze and VELocity (PARSIVEL) disdrometer located in the National center for intensive observation of severe weather at Boseong in the southwest of the Korean peninsula. In addition, time series of RSD parameters, relationship between reflectivity-rain rate, and vertical variation of rain rates-fall velocities below melting layer were examined. As a result, good agreements were found in the reflectivity-rain rate time series as well as their power relationships between MRR and PARSIVEL disdrometer. The rain rate was proportional to reflectivity, mean diameter, and inversely proportional to shape (${\mu}$), slope (${\Lambda}$), intercept ($N_0$) parameter of RSD. In comparison of the RSD, as rain rate was increased, the slope of RSD became less steep and the mean diameter became larger. Also, it was verified that reflectivities are classified in three categories (Category 1: Z (reflectivity) > 40 dBZ, Category 2: 30 dBZ < Z < 40 dBZ, Category 3: Z < 30 dBZ). As reflectivity was increased, rain rate was intensified and larger raindrops were existed, while reflectivity was decreased, shape (${\mu}$), slope (${\Lambda}$), intercept ($N_0$) parameter of RSD were increased. We expected that these results will lead to better understanding of microphysical process in convective rainfall system occurred during short-term period over Korean peninsula.